How are bears so huge? If I ate nothing but berries and salmon I’d probably be really slender.
You might be underestimating how nutrient-rich a steady diet of salmon can be.
According to a ranger in Denali I spoke to: It depends on where the bears live in relation to the food. Coastal grizzlies are much larger because they have plentiful fat and protein sources like salmon. Inland grizzlies that live near glacial streams don’t have that food source and subsist on larger quantities of berries and the like and are noticeably smaller than their coastal counterparts.
So the food sources directly impact the sizes of the animals within the same species. The grizzly I saw in Denali appeared no larger than well-fed black bears I have encountered in the Sierra Nevada range. I say appeared, because it very well may have been larger. But it certainly didn’t look like the ones near the coast.
Kind of an answer, but I’m not a bear biologist.
